Arrays of binding agents (ligands), such as nucleic acids and polypeptides, have become an increasingly important tool in the biotechnology industry and related fields. These binding agent or ligand arrays, in which a plurality of binding agents are positioned on a solid support surface in the form of an array or pattern, find use in a variety of applications, including gene expression analysis, drug screening, nucleic acid sequencing, mutation analysis, and the like.
A feature of many arrays that have been developed is that each of the polymeric compounds of the array is stably attached to a discrete location on the array surface, such that its position remains constant and known throughout the use of the array. Stable attachment is achieved in a number of different ways, including covalent bonding of the polymer to the support surface and non-covalent interaction of the polymer with the surface.
Where the ligands of the arrays are polymeric, e.g., as is the case with nucleic acid and polypeptide arrays, there are two main ways of producing such arrays, i.e., via in situ synthesis in which the polymeric ligand is grown on the surface of the substrate in a step-wise fashion and via deposition of the full ligand, e.g., a presynthesized nucleic acid/polypeptide, cDNA fragment, etc., onto the surface of the array. In many situations where the desired polymeric ligands are long, the latter protocol of depositing full ligands on the substrate surface is desirable.
A number of different protocols have been developed in which full ligands are deposited onto the surface of an array, where such methods include those in which polylysine is adsorbed onto the surface of a glass support, those in which the surface of a glass support is modified via silylation to display various functional groups, and the like.
However, there is continued interest in the development of new protocols for producing arrays via deposition of full ligands onto the surface of the array. Of particular interest would be the development of protocols that provide for covalent attachment of full ligands, e.g., presynthesized nucleic acids, cDNAs and the like, following deposition of the full ligands on the support surface.